1. Field Of The Invention
The present invention generally relates to apparatus and method for ultrasonically bonding web materials, e.g., ultrasonically fusible thermoplastic materials, in a manner adapted for high-speed commercial operations.
2. Description Of The Related Art
U.S. Pat. No. 3,272,682 to L. Balamuth, et al discloses ultrasonically joining thermoplastic sheets with a rotary vibrator having at least one sealing tool at its periphery for rolling contact with the sheet against a back-up roller. The peripheral sealing tools may extend circumferentially and/or axially on the rotary vibrator, to join the sheet along seams either parallel or transverse to the direction of sheet movement.
Russian Pat. No. 785,051 describes ultrasonic seam welding of polymeric materials with a disc tool having a plurality of individual gapped segments applied to a toroidal converter by circular projections, wherein the toroidal converter has separate insulated sections and individual excitation windings for each segment. Material to be welded is fed to the welding zone between a supporting roller (anvil roller) and segments of the disc tool, while current is fed through a slip-ring and excitation windings to individual segments for conversion into ultrasonic energy passed intermittently to the welding zone.